Sag Harbor is a sentimental comedy by American playwright James Herne. It inaugurated Oscar Hammerstein's Theatre Republic, the first Broadway theater on West 42nd Street, on September 27, 1900, starring the author as Capt. Dan Marble. Lionel Barrymore later took up the role Notes Plays by James Herne 1900 plays Long Island in fiction Plays set in New York (state)